Rotor disks for turbomachines, which are shrunk onto a shaft of the turbomachine, for example, and are coupled to rotor blades of the turbomachine, are known from the related art. Passage boreholes for fluids such as oil are formed in the rotor disks. Such boreholes are cavities having small passage cross-sectional areas, which offer advantages for a “secondary air system.”
Rotor disks, in which the passage boreholes are formed as cylindrical boreholes and/or as elongated holes, are already known.